Apparatus for separating materials of different specific weights



R. MAIER July 9, 1940.

APPARATUS FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC WEIGHTS Filed July 30, 1937 ZZZ Patented July 9, 1940 PATENT OFFICE APPARATUS FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC WEIGHTS Rudolf Maier, Stuttgart, Germany Application July 30, 1937, Serial No. 156,598 In Germany July 30, 1936 A 4 Claims. The invention relates to apparatus to eliminate from a gas by means of centrifugal force materials Y of different specific weights floating in the gas or being mixed up with it, or to separate these materials from each other.

Separating by centrifugal forceis the most simple and the cheapest of all means that have been employed for the above purpose. But this method of separating materials has not been sucl0 cessful when applied to-materials with very little difference in their specific weights or 'of an extreme dispersity although theoretically there is no reason to suppose, that centrifugal force should not be able to beused to that end. The necessity however to eliminate for instance dusts of extreme dispersity from gases has led to other means being tried, such as electric dust collectors. But

these and most of the other separating devicesare very expensive and voluminous and do not meet all those requirements which have often .to

be satisfied in modern plants.

The process of the present invention makes it possible to eliminate from gases materials -of unlimited dispersity or separate them from each other, even if there is very little diflerence in their specific weights, bymeans of installations which require very little space and small initial and running cost. The process may even be applied to separate by centrifugal force gases of different density'out of a mixture, such as carbonic oxide out of lighting gas.

The various objects and features of the invention will be apparent from a consideration of the following description and the appended drawing wherein an exemplary embodiment of the invention is disclosed. v

The single figure of the drawing is an axial sectional view illustrating a rotor for separating suspended materials of different specific weights.

A hollow cylinder Ia, adapted for fast rotation, is immersed in the mixture to be dedusted or separated.- Its thick wall is perforated by many channels 2a. One end of the cylinder is closed and the opposite end extends through a housing 3aprovided with a stufiing box 3b and a second stufling box. 30'. At the end of the cylinder there is a coupling la. for a motor 4b. A pipe 5a connects the housing 3a. with a suction pump 51:

H which may be regulated by well-known devices.

Output and speed of the motor must be adjustable within a wide range. It is supPQSed that the 5 cylinder rotates in the open air or in a wide channel filled with gas and dust.

The gas mixture to be de-dusted is forced along 65 the channels in the rotating cylinder with any desired speed in the direction of the arrows. All particles must now take part for some time in the rotation of the cylinder la. Thusthey are exposed for some time to the influence of a field of centrifugal force driving them outwards oif 5 the cylinder, or in an opposite direction tothe flow which'is taking them to the cylinder axis. The field of centrifugal force extends not only to the interior of the cylinder and to the channels 2a; but also beyond its exterior surface as far as 10 its rotation creates a noticeable following wind. It should be observed that the cylindermust not have any projecting parts, which would have an effect similar to that of propeller or -ventilator vanes pressing away the gas in front of it. The 15 cylinder will transmit its rotation to the gas sur-i roundingcit by friction in such manner as to form a purely rotating laminar flow- This flow creates a rotating layer of gas around the cylinder which according to its nature as a following wind 2() is of a very stablecharacten.

The duration of the action of the field of centrifugal force on the gas and the particles flowing with it may be regulated from fractions of secends up to any desired period by adjusting the 25 4 speed of the suction pump 5b. The extent and strength of the field of centrifugal force through which all particles must pass,- are also determinable within wide limits. For instance that part of the field of centrifugal force which is acting 30 in the interior of the cylinder may be made long or short by employing a cylinder of corresponding thickness or by inserting into it pipes of corresponding lengths'. The part of the field of centrifugal force which is created outside by the fol- 35 lowing wind, may also be determined by an adequate enveloping of the cylinder by means of a casing 6a. and a corresponding speed of rotation. The strength of the field of centrifugal force also may be regulated from zero up to very 4 high values, because it is possible to give such rotorsperipheral speeds of hundreds of metres per second.

It is therefore possible to expose all particles of the gas mixture to a determinable and adjust- 45 able field of centrifugal force during a determinable time andover a determinablelength of way, the three factors being determinable and adjustable independently of one another. The counter action of centrifugal force and suction force 50 makes it possible to influence very exactly the process of separation of the gas and the particles flowing with it in such manner that the gas sucked off the mixture willitake with it only welldefined parts of the finest or lightest components.

regulable speed through that field of centrifugal force opposite to the direction of the centrifugal force. The rotating cylinder acts chiefly as a means for creating the field of centrifugal force, but not as a means for collecting the dust out of the gas mixture and throwing it off in the manner of many devices of the prior art. These devices are usually provided with vanes as used on ventilators or blades, or rotating combs and brushes, and it is these parts themse1vesnot a field of centrifugal force created by them within a laminar rotating'layer of gas-which form the chief obstacle opposed to the flow and which retain the particles not desired. A rotating body acting as dust collector cannot in addition be used for sorting out, because it will eliminate particles regardless of their size. The rotating cylinder or other parts used in the present invention are therefore designed in such manneras to reduce their capacity of catching dust particles and the like as much as possible.

In the arrangement described the speed of rotation of the gas mixture is highest immediately on the surface of the rotor. This is in contrast to thewell-known cyclone apparatus. The flow in such devices is more disturbed as it approaches the axis. This is the consequence of the whirlwinds being roused in such centrifugal separators, and which chiefly prevent the separation of the finer particles moving along a slowest I speed. In the apparatus according to the invention it is just the centre of the mixture which is led in the best manner.

The number and size of the perforations may vary within wide limits, as well as the shape of the rotor and its size in relation to the container in which it rotates and also the depth up to which the rotor is immersed into the mixture to be treated. The perforated rotor allows of a continuous run of the apparatus for any length of time, choking of the channels being avoided by the constant circulation or by flinging it off by an occasional acceleration of the circulation.

The shape of the container'in which the cylinder is arranged may be chosen at liberty. In many cases there is no need at allfor a container, as when extracting one of the components of atmospheric air.

It does-not matter much in which direction the mixture enters the container inside which the rotor revolves.

The process and apparatus described permit large quantities of gas to be de-dusted or sorted. The invention also enables gases of different density to be separated. The possibility of separating gases by centrifugal force is well-known in the art. But by the process and the apparatus of the present invention, a'suitable arrangement has been created by means of which gases may be separated mechanically in any quantities desired, because the effect of the centrifugal force creases the more it approaches the rotor wall or enters the rotor through the material out of which it consists or on account of its particular shape. By means of an adequate raising of the centrifugal effect and a sufficiently long duration of this'eflect the separation takes place inside this'gas layer. The quantities passing the channels in the rotor is regulated according as to whether a full or partial separation is desired. In the case of gases-.-as pointed out already-the condition of the surface of the rotor-is of great importance for the formation .of the gas layer. The same isthe case with the physical or chemical affinity of the material of the rotor to the different gases, for example a platinum plated surface may be favorable for separating hydrogen.

-I claim:

1. Apparatus for separating one constituent from a gaseous mixture by centrifugal force comprising,.a hollow rotor of substantially cylindrical shape having inside and outside substantially smooth surfaces, a closed end. the wall of said rotor being relatively thick and apertures in the wall, a gas-duct connecting the hollow inside with a container, means for rotating said rotor around its axis at high speed creating and stabilizing a rotating laminar flow of the gaseous mixture around the wall, said flow forming a field of centrifugal force, and means to suck gas off said field through said apertures into said hollow inside and further through said gasduct into said container.

I 2. Apparatus for separating one constituent from a gaseous mixture by centrifugal force comprising, a smooth cylinder having a relatively thick wall provided with radially extending channels, ahousing and means creating suction therein, means for rotating said cylinder around the axis thereof at a relatively high speed so as to create a rotating laminar flow of the gaseous mixture around the wall of the cylinder by friction between the mixture and the wall of the cylinder, and means connecting the interior of said cylinder with the housing so as to suck a part of the mixture from the interior of the cylinder without disturbing the laminar flow of the gaseous mixture.

3. Apparatus for separating one constituent from a gaseous mixture by centrifugal force comprising a cylinder having a relatively thick cylinder having openings therein providing rela-- tively long channels through the wall of the cylinder, a tubular member extending axially from the cylinder and having openings therein, a casing surrounding said tubular member provided with bearings for rotatably supporting the cylinder, means for driving said cylinder at a relatively high speed so that thefriction of the smooth wall with the gaseous mixture will create a rotating laminar flow of the gaseous mixture around the wall of the cylinder, and suction means for drawing a part of the gaseous mixture into said housing without disturbing the flow of the gaseous mixture adjacent the cylinder wall.

'4. Apparatus for separating one constituent smooth wall and a closed end, the wall of said from a gaseous mixture by centrifugal force comfor rotatably supporting the cylinder, meansv for driving said cylinder at a relatively high speed so that the friction of the smooth wall with the gaseous mixture will create a rotating laminar flow of'the gaseous mixture around the wall of the cylinder, suction means for drawing a part of the gaseous mixture into said housing for supplying the gaseous mixture to the ex-- terior of said cylinder. v v

. RUDOLF' MAIER. v 

